1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly to a manufacturing method of a liquid crystal display device adapted to improve a viewing angle, an aperture ratio, and a contrast ratio.
2. Discussion of the Related Art
Display devices have been developed greatly as information communication is developed, and are taking root as necessities to the moderns. A liquid crystal display device among these display devices is rapidly rising as a next generation display device because it consumes low power, has a fast response speed and small size.
The liquid crystal display device includes a light source and a liquid crystal panel. The light source provides light to the liquid crystal panel. The liquid crystal panel drives liquid crystal by use of electric fields. The liquid crystal display device displays a picture by controlling the transmittance of the light which is transmitted through the liquid crystal panel by driving the liquid crystal. At this moment, the liquid crystal has refractive index anisotropy, thus the liquid crystal display device has a narrow viewing angle.
In order to improve the viewing angle, the liquid crystal display device has a common electrode and pixel electrode which are bar-shaped and located on a pixel of substrate. The pixel electrode and the common electrode are alternately arranged by a fixed distance. Herein, when a data voltage is applied to the pixel electrode and a common voltage to the common electrode, a horizontal electric field in a horizontal direction to the substrate is formed. At this moment, the liquid crystal is driven by the horizontal electric field, thus it is possible to provide a good image in the characteristic of viewing angle, i.e., the viewing angle is symmetrical.
However, the horizontal electric field is formed in a separate space between the pixel electrode and the common electrode, but it is not formed in the upper part of the common electrode and the pixel electrode. Hereby, the liquid crystal disposed in the separate space is driven, but the liquid crystal disposed in the upper part of the common electrode and the upper part of the pixel electrode is not driven. Consequently, a light leakage in the upper part of the pixel electrode and in the upper part of the common electrode is generated, thus the contrast ratio is decreased and the aperture ratio is deteriorated.
Accordingly, the liquid crystal display device of the related art has a problem in that the contrast ratio and the aperture ratio deteriorate when the pixel electrode and the common electrode are disposed on the pixel for improving the viewing angle.